The invention relates to an undercarriage, preferably for a crawler-mounted crane, comprising a crawler track which runs on a crawler carrier and which consists of base plates articulatedly connected to one another, with cams being formed on the base plates which engage into grooves of rollers arranged in the crawler carrier, with them laterally centering the crawler track under the rollers.
A crawler track in accordance with the prior art is shown, for example, in FIG. 1. Part of an undercarriage 10 is shown there which comprises a crawler carrier 12 on which a crawler track 14 runs which consists of base plates 16 articulately connected to one another. It can in particular be clearly seen from the sectional representation in accordance with FIG. 1a that the base plates 16 have cams 18 approximately centrally. The cams engage into grooves 20 which are provided around the periphery in rollers 22 (cf. FIG. 1a). The rollers are arranged in the crawler carrier 12. The crawler track 14 is driven by a drive wheel 24 in a conventional manner.
In the previously described constructional embodiment, the problem in particular exists with the crawler-mounted crane that the track is very heavy due to the high forces and consequently sags very pronouncedly with the slightest ground irregularities, as is indicated in FIG. 1. In this case, the lateral guidance of the crawler track 14 by the cams 18 of the base plate 16 is no longer ensured. The cams 18 can, however, not be made higher since then the diameters of the rollers 22 would have to be made larger in order to be able to accommodate the higher cam in the corresponding groove 20 running around the periphery. This is, however, not possible since then it is not possible to provide enough rollers 22 in the undercarriage 10 and thus the load on the individual base plate 16 increases in a non-permitted manner.
If a longitudinal movement is made with a sagging crawler track 14, as is shown in FIG. 1, the lower track carriage contacts the ground and the crawler carrier pivots over the track. The cams 18 are then no longer located beneath the ring-shaped cut-out 20 of the rollers 22. On a further forward movement of the crawler undercarriage, the rollers 22 are thereby pushed toward the tips of the cams 18. Due to the high weight of the crane, this results in severe damage to the cams 18 on the base plates 16. If the crane operator does not notice this damage, the crawler track 14 can jump off the crawler carrier 12. The repair of damage of this type results in a large effort of time and equipment.